Advances in technology have led to the development of small medical devices that can be implanted within a living organism, such as a human, to provide treatment or monitoring. Powering such implantable medical devices may be challenging. An onboard battery of an implantable medical device may provide a limited amount of power due to a finite amount of energy that can be stored in the onboard battery. Replacing a battery of the implantable medical device may be expensive and inconvenient. For example, invasive surgery may be needed to replace the battery of the implantable medical device after it is implanted in a patient. Due to these and other concerns, some implantable medical devices may use rechargeable batteries.
However, charging a rechargeable battery of an implantable medical device may present other challenges. Charging inefficiencies may result in long charging times that may be undesirable for patients and may reduce compliance with a charging procedure. Such inefficiencies may be dependent on various factors that may be associated with use of a charging device to facilitate the charging. Some factors include alignment, position, and distance between the charging device and the implantable medical device.